Query a table where combinations of fields do not exit?

Question

I apologize for the poorly worded title :(

I have three tables.

1. Table MARA: Articles and their descriptions.
2. Table MARC: Article to site assortments.
3. Table T001W: Sites and their locations.

I'm trying to find the missing records in MARC that demonstrate an article is NOT assorted to a site. See the attached table for a rudimentary example.

Here, there are 2 articles (A & B) and 4 sites (1, 2, 3, and 4). I'm looking for the query that can search MARC based upon the articles in MARA and the sites in MARC and tell me what doesn't exist. The right answers in this example would be A-4, B-1, and B-4.

Alternatively, I can provide the MARA and T001W values in a list in the query to avoid any joins. MARA will have ~1,500 values and T001W will have 2,000.

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<table class="tg">
  <tr>
    <th class="tg-amwm" colspan="2">MARA</th>
    <th class="tg-8m24"></th>
    <th class="tg-amwm" colspan="2">MARC</th>
    <th class="tg-8m24"></th>
    <th class="tg-amwm" colspan="2">T001W</th>
  </tr>
  <tr>
    <td class="tg-8zwo">Article</td>
    <td class="tg-8zwo">Desc</td>
    <td class="tg-8m24"></td>
    <td class="tg-8zwo">Article</td>
    <td class="tg-8zwo">Site</td>
    <td class="tg-8m24"></td>
    <td class="tg-8zwo">Site</td>
    <td class="tg-8zwo">Continent</td>
  </tr>
  <tr>
    <td class="tg-0lax">A</td>
    <td class="tg-0lax">Spoon</td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax">A</td>
    <td class="tg-0lax">1</td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax">1</td>
    <td class="tg-0lax">NA</td>
  </tr>
  <tr>
    <td class="tg-0lax">B</td>
    <td class="tg-0lax">Fork</td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax">A</td>
    <td class="tg-0lax">2</td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax">2</td>
    <td class="tg-0lax">SA</td>
  </tr>
  <tr>
    <td class="tg-0lax"></td>
    <td class="tg-0lax"></td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax">A</td>
    <td class="tg-0lax">3</td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax">3</td>
    <td class="tg-0lax">EU</td>
  </tr>
  <tr>
    <td class="tg-0lax"></td>
    <td class="tg-0lax"></td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax">B</td>
    <td class="tg-0lax">2</td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax">4</td>
    <td class="tg-0lax">AS</td>
  </tr>
  <tr>
    <td class="tg-0lax"></td>
    <td class="tg-0lax"></td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax">B</td>
    <td class="tg-0lax">3</td>
    <td class="tg-8m24"></td>
    <td class="tg-0lax"></td>
    <td class="tg-0lax"></td>
  </tr>
</table>

---

Edit: Adding text tables and sample data.

Table MARA
Article | Description
A | Spoon
B | Fork

Table MARC
Article | Site
A | 1
A | 2
A | 3
B | 2
B | 3

Table T001W
Site | Desc.
1 | NA
2 | SA
3 | EU
4 | AS

Answer 1

If I understand correctly, you can use a cross join to generate all combinations of sites and articles and then remove the ones that exist:

select s.site, a.article
from sites s cross join
     articles a left join
     marc m
     on m.article = a.article and
        m.site = s.site
where m.article is null;

I renamed the tables so the query logic is easier to follow.